Users have to manipulate a wireless communication terminal with their hand to turn on/off its power or change the ring mode from a bell-ringing mode to a vibration mode or from the vibration mode to the bell-ringing mode.
The wireless communication terminals forgotten to be set at vibration mode in public places such as a performance site, a hospital and so on, their bell-ringing cause a great deal of noise pollutions and further may serious accident of mechanical malfunction by the radio wave of the wireless communication terminals. The use of wireless communication terminals are staunchly restricted in regions such as the hospital or an airport where precision instruments operates, because a radio frequency (RF) signal may affect medical instruments or precision machinery.
Accordingly, a method of radiating low-powered jamming signals corresponding to the frequency band of the wireless communication terminals and keeping the transmit and receipt functions of the terminal away from working is put to practical use lately at public places, e.g., performance sites and so forth. Also suggested is a method generating a certain control signal and switching the ring mode of the mobile terminals from the bell ringing to the vibration.
However, these conventional methods have a shortcoming that it cannot basically block the RF radio waves that affect the operation of the medical machines and the precision machinery in a communication restriction area such as the hospital or the airplane.
Therefore, a user needs to turn off his wireless communication terminal himself to keep the affection of the RF in such places. However, this requires a lot of attention from the user, which leads to the need for an apparatus that automatically switches its mode.
This kind of apparatus needs a function to restrict the communication of the mobile terminal, i.e., RF radiation itself, by control signals from the outside. Also, it needs a function to release it back to communication mode when the user is out of the communication restriction area.